Steam hairsetters are known in the art. Typically, a steam hairsetter comprises a plurality of steamable hair curlers and a steamer for generating steam from water in a reservoir to heat the hair curlers via the steam. The hair curlers are placed, one at a time, on a post of the steamer to allow the steam escaping from a steam outlet under the post of the steamer to moisten an absorbent portion of the curler (typically a polymeric foam). See, e.g, commonly assigned U.S. Pat. Nos. 3,759,271 and 4,453,554, incorporated herein by reference. Examples of steamers heretofore used in connection with steamable hair curlers can be found in commonly assigned U.S. Pat. Nos. 5,255,694, 5,309,930 and 5,355,291, also incorporated herein by reference. Other examples of steamers can be found in U.S. Pat. Nos. 3,610,879, 3,971,913, 3,714,391 and 4,463,248.
Prior art steamers typically employ one or more electrodes that extend into a reservoir for heating water therein when the electrodes have been energized. The electrodes are of commonly of a carbon steel composition and are adapted to generate heat when either 110 VAC or 220 VAC power has been applied. The heat boils water in the reservoir to generate the steam. The steamer may be adapted to be powered by both 110 VAC and 220 VAC sources. In these so-called "dual voltage" steamers, the electrodes are usually designed to be powered at 110 VAC, and the steamer usually comprises rectifier circuitry that effectively converts the output of a 220 VAC source to 110 VAC power. Thus, circuitry and/or switching is needed to render such steamers "dual voltage" capable. If the user neglects to switch the steamer from 110 VAC to 220 VAC before the steamer has been plugged into a 220 VAC source and used, hazardous electrical conditions may result and the steamer may be damaged. Conversely, if the user neglects to switch the steamer from 220 VAC to 110 VAC before the steamer has been plugged into a 110 VAC source and used, the steamer may not operate properly. In addition, if for some reason, the user exposes the electrodes, he or she may be severely injured.
One characteristic of these electrodes is that both their power consumption and heat output is relatively high. By way of example, one presently available steamsetter steamer available from the assignee hereof that uses these electrodes requires about 725 watts of input power (5.8 amps at 125 volts).
Many prior art steamers have a single reservoir and they heat all of the water that has been poured into the. reservoir by the user. Some purport to have a separate "boiling chamber" in fluid communication with a main reservoir such that, it is said, only the water in the boiling chamber is heated to boiling and the water in the main reservoir is not substantially heated. See, e.g., U.S. Pat. Nos. 3,714,391 and 4,132,883. However, as seen in these patents, the volumetric capacity of the boiling chamber is still rather large, which means that a large amount of water will be heated to boiling temperature at any given time. These steamers also employ the same type of electrodes previously discussed, i.e., they have relatively high heat output.
In addition, it is likely that the water in the main reservoirs of the steamers described in the above mentioned '391 and '883 patents will become heated during normal operation. This is due, at least in part, to the high heat output of the electrodes employed therein, the size and/or number of the fluid flow orifices needed between the main reservoir and boiling chamber needed to replenish the boiling chamber at a sufficient rate, and the relatively large volume of hot water present in the boiling chamber at any given time (at least in relation to that present in the main reservoir).
One other characteristic of these prior art steamers is that it can take quite some time for the water in the reservoir to become heated sufficiently to reach boiling temperature because the electrodes rely upon the conductivity of the water in the reservoir to complete the electrical circuit between the electrodes. For this reason, it has generally been recommended that salt be added to the water because salt increases the conductivity of the water. Thus, the addition of salt improves the electrical function of the electrodes and reduces the amount of time that it takes for the steamer to begin generating steam.
It is desirable to provide a steamer that has dual voltage capability, yet does not require voltage changing switching and/or circuitry. It is also desirable that such steamer employs a heating element that does not have the above described. drawbacks of conventional electrodes and that has relatively low power consumption. It is further desirable to provide a steamer that does not require the addition of salt to the water to provide quick boiling. Finally, it is desirable that such steamer have a heating chamber that is thermally isolated from a main reservoir such that the water in the main reservoir is not heated, and that the volumetric capacity of the heating chamber be very small. The present invention satisfies all of these goals.